I want to marry a man but his first wife name has ben mantioned in his pasport... what step shoud be taken oso there will be no problem in fiture if I want to go and live with him in abroad...

As long as he is divorced what does it matter if his first wife is mentioned on his passport?

What do you mean she is "mentioned"? Is it a joint passport? There should be no problem with that, but obviously, if it bothers you, he can have a new passport issued.